Amines as leaving groups in nucleophilic aromatic substitution reactions

Structural and spectroscopic investigation of 1-amino-2,4-dinitrobenzenes

“…À40.3(7) À57.9(6) À45.1 ( À150.1(6) À156.1(5) 178.4(5) À158.8 (2) group in the latter causes the rotation of both the o-nitro groups and the substituent on C(1). 15 Conformational details of non-aromatic rings are summarized in Table 3(b), where the displacement deformation parameters 16 and the corresponding puckering parameters, 17 as calculated by PARST95, 10 are shown.…”

“…It has been suggested that if this interaction decreases, carbon-1 can be attacked as readily as when substituted by other groups, and the amine is displaced. 2 The interaction between the aromatic ring and the amine decreases if the amine is rotated out of the aromatic plane.…”

Medium Effect on the Reaction of N‐Butyl‐2,4,6‐trinitroaniline with NaOH

“…[6] [ product observed in the reactions of N-butyl-2,4-dinitro-6-(trifluoromethyl)aniline and N-propyl-2,6-dinitroaniline. [8] Under the same reaction conditions, N-butyl-2,4,6-trinitroaniline (3) gives only 2,4,6-trinitrophenol (4) with 0.2  NaOH, whereas 46 % of 5,7-dinitro-2-propyl-1H-benzimidazole 3-oxide (5) along with 4 is obtained with 0.01  NaOH [Equation (1)]. [7] (1)…”

“…Nucleophilic displacement of the leaving group by hydroxide within 3-nucleophile σ complexes was previously proposed and it was suggested that this facilitates the displacement of the leaving group. [1,2,15] The rate law for the mechanism shown in Scheme 4 is given by Equation (9) which has the same mathematical form as Equation (5). (9) The experimental data for k obs fit to Equation (9) using the values of the other calculated equilibrium constants shown in Table 3, giving k 0 = 1.6 ϫ 10 -3  -1 s -1 and k 5 = 3.3 ϫ 10 -4  -1 s -1 .…”

“…If the nitrogen atom of the amino group is rotated out of the aromatic plane, this interaction decreases and the amine can be displaced. [1,2,24] We have previously reported that, based on structural calculations and spectroscopic investigations, rotation and bending of the amino group occurs in compound 3.…”